Ammunition.



UNITED STATES PATENT OFFICE.

I WILLIAM H. BUELL, OF NEW HAVEN, CONNECTICUT, ASSIGNOR, BY MESNE ASSIGN- MENTS, T UNION METALLIC CARTRIDGE COMPANY, OF BRIDG-EPOR-T, CONNECTICUT,

A CORPORATION OF CONNECTICUT.

AMMUNITION.

Specification of Letters Patent. 7

Patented Oct. 12, 1915.

No Drawing. Original application filed October 21, 1913, Serial No. 796,441. Divided and application filed June '18, 1914, Serial No. 845,875. Divided and this application filed December 1, 19144 Serial No.

To'all whom it may concern Be'it'known that I, WILLIAM H. BUELL, a citizen of the United States, residing at New Haven, in the county of New Haven, State of Connecticut, have invented a new and useful Improvement in Ammunition;

' andI do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to a priming charge for use in igniting explosives, which is of especial utility in igniting the various f smokeless and black powders when used in center fire and rlm fire ammunition.

'1 The purpose of my invention is to produce a priming charge which is partlcularly sultedfor use with powders as now employed in firearms, and particularly small arms, such charge producing'an explosion of not too -.great local pressure, and of sufiicient heat,

dues.

andleaving substantially no harmful resinatingsalt of hydrazoic acid with a suitable nitrated organic body. For instance, I may add 3 parts by weight of nitro cellulose (preferably high nitrogen insoluble) to 1 part of lead hydrazoate, and mix the same to produce a substantially homogeneous product. While the detonating salts of hydrazoie acid are too brz'somt for use alone in firearms, and 'especlally in small arms, the mixture above described will be found suitable '1 7 for such use, the local pressure of the ex plosion being reduced, and its heat increased. Substantially no residue is left which may injure the shell or the bore .of the arm. While I prefer to use the lead salt, I may use other detonating salts of hydrazoic acid, for

instance the silver'salt'; I may even use the mercury salt, although this salt does not give all the contemplated advantages, as it leaves a residue which is apt to form a harmful amalgam with the metal of the shell.

In .place of the nitro cellulose, I may employ some other suitable nitrated organic body such for instance, as nitrated starch, the aromatic nitro compounds as trinitrotoluene; the nitro derivatives ofcarbamid or urea as nitro urea; the aromatic diazo salts as diazo benzene nitrate; and the aromatic diazo amido compounds as diazo amido benzene. While the proportions most suitable for the mixture may difier with various substances, and also with various powders in connection with which the mixture is to be used, they are easily determined by anyone skilled in the art. I desire it to be understood that it is possible that some nitrated organic bodies, in combination with a detonating salt of hydrazoic acid, may not produce a primer having the explosive qualities above described, and that I therefore include in my invention the use of such bodies only as will in such combination produce such a primer. It is also to be understood that the term detonatingsalt of hydrazoic acid as used in the art, and by me in this specification, refers only to a salt of the heavy'metals, and does not include salts of the alkali metals, although such salts may have slight detonating properties under certain abnormal conditions.

In its more specific form my invention further contemplates the presence of a third substance for the purpose of leaving an alkaline residue suited to neutralize wholly or measurably the acid residue left by the burning of the powder, particularly of smokeless powder, and also any acid residue which might be'left from the explosion of the other ingredients of the primer. This substance 'is a salt or other compound which eith r is not affected by the explosion or is broken up by the explosion, and in either case leaves aresidue suitable for the purposes indicated. I may use sodium or potassium carbonate, barium nitrate, or potassium nitrate. I prefer, however, to use an alkali metal salt of hydrazoic acid, or an alkaline earth metal salt, ora' double alkali metal and metal salt, of such acid; such as for instance, the sodium salt, or the potash salt, or the potassium cobalt salt of such acid, The use of these last mentioned substances has the further great advantage of producing an increased flash, in addition to causing the residue of the explosion of the primer to be alkaline.

I may for instance mix 6 parts by weight of lead hydrazoate and 11 parts of nitro cellulose (preferably the high nitrogen insoluble) with 3 parts of sodium hydrazoate. It will be found that this mixture when exploded, will have all the advantages above claimed for the mixture of the lead salt and nitro cellulose alone, and will have'the additional advantages of an increased flame, and of abeneficial alkaline residue. The proportions may have to be varied under different circumstances and conditions, and with different materials and for different powders, but they can readily be ascertained by anyone skilled in the art. It is possible that some compounds which upon ignition leave an alkaline residue and particularly some members of the group of alkali metal, alkaline earth metal and double alkali metal and metal salts of hydrazoic acid, may not operate as described in the combinations indicated, and, if so, they are not included in my invention. In my claims I group the above mentioned salts of hydrazoic acid under the general term of alkali metal salts of hydrazoic acid.

The 'mixtures above specifically referred to, either of two substances, or of three substances, constitute a fine white or light colored mass which may be moistened with a gimi solution and then introduced into the primer caps, where it is seated under heavy pressure, and may then, if desired, be covered with paper or foil, or by a thin film of collodion. An anvil of any suitable construction may then be inserted into the cups. When the primer is to be used in rim fire ammunition it is preferably given the treatment with the gum solution and then driven into the annular rim of the cartridge shell by centrifugal force. It may then be covered by collndion.

I have found that I may increase the sensitiveness of the mixture to a high degree. by first mixing the nitrated organic body, as for instance the nitro cellulose, with the alkaline residue producing salt, for instance the sodium hydrazoate, treating the mixture with amylaceta'te or other suitable solvent, in sufficient amount to obtain the proper consistency, permitting the mixture thus treated to harden and then grinding the same, and then adding to the ground substance the detonating salt, as for instance, lead hydrazoate. Glass may be added at the same time with the detonating salt.

By this operation I obtain a primer in which the alkaline residue producing salt is more intimately mixed with the nitrated organic body than would be the case if all three ingredients were simultaneously mixed 6 in a dry state, and the sensitiveness of the mixture is thereby greatly increased. I obtain moreover a further useful result, namely that the particles of the alkaline residue producing salt are surrounded by a film or covering of the nitrated body, so that such particles are measurably insulated from contact with the metal. of the shell, and interaction between the two is measurably prevented.

The primer mixtures described in the above specific examples, especially those containing the third ingredient, are homogeneous in character and of the proper i iting quality, so that a hot and uniform alne is produced without excess of local pressure and with a minimum of harmful residue or none at all. The flame produced has the proper velocity and intensity to ignite the powder charge before imparting any appreciable motion to it before ignition, and thus efiects an explosion having the maximum pressure near the breech of the gun, and not one which is delayed until the charge nears themuzzle, the portion of the barrel least adapted to withstand bursting pressure.

\Vhile I may add other substances to my primin mixture, I prefer not to do so. Thus, 0 lorate of potash, or some other oxidizing compound, such as the perchlorates, nitrates and peroxids of barium, potassium, etc., may be added to the mixture, or in part substituted for certain ingredients, but their presence is usually undesirable owing to the production of an increased local pre8- sure.

The subject matter of my invention must not be confused with detonators, nor with priming charges which are not suitable for use in firearms. To make a priming charge suitable for use in firearms it must not be too violent in action, but must, on the other hand, be capable of being exploded by the action of the firing pin or other firing mechanism striking against the casing which contains the charge. When I refer in my claims to a casing I mean to include in such term any container which is suitable for the purpose indicated, namely to permit the charge to be acted on by the firing mechanism.

I have also found that a mixture of a detonating salt of hydrazoic acid and an alkali metal salt of such acid forms a priming charge adapted for use in firearms. Such charge may be composed for example, of 45 parts by weight of lead hydrazoate and 55 parts by weight of sodium hydrazoate. In such a charge the brisant effect of the lead salt is toned to a sufficient extent and a maximum value is obtained with regard to alkaline residue. The alkali metal salt of a hydrazoic acid may also be mixed with a suitable non-gaseous fuel and a suitable oxidizing compound to produce a successful priming charge. Such charge may be comcharge the alkali metal salt has for its prin cipal purpose to neutralize measurably the injurious acid residue formed by the reaction between the other ingredients of the charge. The alkali metal hydrazoate, as used in my invention, is of particular value because it is itself explosive and therefore adds this value to the charge in addition to its value in leaving an alkaline residue.

It will of course, be understood by those I skilled in the art that when I speak of the formation of a harmful'amal'gam with the metal of the shell, I have reference to a brass shell, because cartridge shells, and especially those used in rim fire ammunition,

' have been made substantially exclusively of copper (but only to a limited extent in this country, so far as I am aware) or of brass (as I have already stated in my Patent No. 1,027,814, dated May 28, 1912) and no harmful amalgam is formed in practice when a mercury primer is used with a copper shell.

This application is a division of my application Serial Number 845,87 5, filed J une 18, 1914, directed to the invention of a charge containing a detonating salt of hydrazoic acid, a nitrated organic body and a compound which upon ignition will leave an alkaline residue, this last mentioned application being itself a division of my application, now Patent No. 1,106,343, dated August 4, 1914, in which the invention of a casing and a charge therein containing a detonating salt of hydrazoic acid and a nitrated organic body, is claimed.

I claim:

1. A rim fire cartridge comprising a shell made of brass and having in its head a circular recess, and a non-mercuric priming compound in said recess. I

2. A rim fire cartridge comprising a bullet, powder, a shell made from brass and having a head provided with a circular recess and a non-mercuric priming compound in said recess.

In testimony whereof, I have hereunto set my hand in the presence of two subscribing witnesses.

WILLIAM H. BUELL.

Witnesses:

FRrrz v. BRIESEN, FRANK F. KIRPATRIQK.

Copies of this patent may beobtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

